A salesman based in Berlin with special occupation status, Niedermayr was like a traveller between the worlds in German motorsport, starting his career with an East German-built BMW special in 1949. As was the fashion at that time, the car was a so-called “Intertype”, which meant it was an open-wheel two-seater with detachable headlights and fenders and, in principle, could be used as either a sports car or in Formula 2 races.

Nevertheless, 1950 saw him taking part only in sports car races in both parts of the divided country with the highlights being 2nd places in the Schauinsland hillclimb, the Solitude and at the East German Sachsenring together with a couple of wins in the comparatively minor East German events at Halle and the Sternberg hillclimb. That year, Niedermayr was also the first driver since the war to make test runs on the Avus track to demonstrate its suitability for taking up racing again.

For 1951, he upgraded his car with a new Veritas Meteor engine replacing the BMW 328 under the bonnet, but the increase in performance was not good enough to achieve any remarkable results. Either way, he must have impressed Mercedes-Benz team director Neubauer enough to invite him into the Le Mans team for 1952, where together with Theo Helfrich he finished second behind his team colleagues Lang / Rieß. Around the same time, he was also very busy on national level, taking over the AFM single seater of Fritz Rieß for Formula 2 races. He took this car to a superb ninth place finish at the German Grand Prix.

It was in this old Meteor-engined BMW special that he became the tragic figure of Germany’s worst motorsport catastrophy when it broke a wheel while flat-out at the ultra-fast Grenzlandring and slid into the spectators, killing 13 people and leaving a further 42 injured. Niedermayr himself came out with only comparatively light injuries and was able to continue his career as co-founder of the Berlin-based racing team “Renngemeinschaft Berlin-Halensee”, driving Porsche Specials in sports car events with some success until 1954, together with a single Formula 1 appearance in Hans Klenk´s rather outdated Veritas Meteor streamliner on his “home ground” at the Avus race.